The present invention relates to antitheft devices for use as attached to commodities for preventing the commodity from being stolen, and more particularly to antitheft devices comprising a tag performing the function of preventing theft occurring upon escaping from a control area, and a member for attaching the tag to the commodity.
FIGS. 9 to 15 show an antitheft device already proposed (Japanese Patent No. 2849048). The device comprises a tag 15 having a flat housing 16 composed of a lower half segment 17 and an upper half segment 18, and a member 2 for attaching the tag 15 to a garment or like commodity 9 as shown in FIG. 9.
With reference to FIG. 10, the housing 16 of the tag 15 has enclosed therein a sensor 40 which performs a specified theft preventing function when the tag 15 as affixed to the commodity is to be brought out of the store past a gate to actuate a theft alarm device installed in the gate.
With reference to FIG. 15, the attaching member 2 comprises a button 22 in the form of a disk, and a pin 21 projecting from the rear side of the button 22. A pinhole 18a is formed in the upper half segment 18 constituting the housing 16 for inserting therethrough the pin 21 of the attaching member 2 as shown in FIG. 11. As seen in FIG. 12, the lower half segment 17 constituting the housing 16 is provided with a cylindrical portion 17a for the outer end of the pin 21 of the attaching member 2 to fit in (see FIG. 10).
With reference to FIG. 14, a spring clamp member 3 made of sheet metal is disposed inside the housing 16 of the tag 15. As shown in FIG. 13, the spring clamp member 3 includes a main body 31 in the form of a flat plate and provided with a pair of clamp pieces 32, 32 for clamping the pin 21 of the attaching member 2 therebetween. The clamp pieces 32, 32 have outer end faces providing a clamp portion 34. The main body 31 has a circular hole 35 formed therein and a spring piece 36 projecting therefrom.
As shown in FIG. 12, the housing lower half segment 17 has a stepped cylindrical portion 17b positioned away from the cylindrical portion 17a. The spring clamp member 3 is rotatably supported on the housing lower half segment 17 by the stepped cylindrical portion 17b fitting in the circular hole 35 as seen in FIG. 14. The clamp member 3 has its spring piece 36 retained at the outer end thereof on the lower half segment 17 by engagement therewith. The spring piece 36 is elastically deformed by counterclockwise rotation of the main body 31, giving a clockwise repulsive force to the main body 31.
Referring to FIG. 9, a small opening 13 is formed in the housing 16 of the tag 15. The opening 13 communicates with the space wherein the clamp member 3 is installed through an inlet passage 14 formed in the housing lower half segment 17 as shown in FIG. 14. With the tag 15 attached to the commodity 9 by the attaching member 2 as seen in FIG. 9, the pin 21 of the attaching member 2 is clamped by the spring clamp member 3 (see FIG. 10), whereby the attaching member 2 is prevented from being pulled out.
If the tag 15 as attached to the commodity is to be brought out of the store past the gate, the sensor 40 incorporated in the tag 15 receives a radio signal (e.g., lines of magnetic force) from the theft alarm device installed in the gate, and transmits a radio signal (e.g., altered magnetic field) to a theft preventing system in response to the received signal. Consequently, an alarm incorporated in the system is actuated, notifying salesclerks of the theft. When the pin 21 is to be released from the clamp member 3 for the salesclerk to remove the tag 15 from the commodity, an unclamping probe 7 shown in FIG. 9 is used.
With reference to FIG. 15, the forward end of the probe 7 is inserted into the clamp member accommodating space from the housing opening 13 through the inlet passage 14 to push the main body 31 of the clamp member 3 with the probe end against the elasticity of the spring piece 36. This rotates the clamp member 3 counterclockwise, thereby disengaging the clamp portion 34 of the clamp member 3 from the pin 21 of the attaching member 2 to unclamp the pin 21. As a result, the attaching member 2 can be removed.
However, since the pin 21 of the attaching member 2 clamped by the clamp member 3 as shown in FIG. 10 can be cut at its base portion with a simple tool, the antitheft device has the problem of suffering an incident in that the tag 15 as attached to the commodity 9 is separated therefrom by cutting the pin 21 of the attaching member 2 to bring the commodity 9 only out of the store unlawfully.
Accordingly, it appears useful to take a countermeasure by providing a sensor on the tag 15 for detecting the separation of the tag 15 from the commodity by the cutting of the pin 21. Although it is required that the tag 15 for use as attached to the commodity be compacted to the greatest possible extent, there arises the problem that the provision of the sensor makes the tag 15 larger in size.
An object of the present invention is to provide an antitheft device which is capable of reliably preventing the foregoing wrongful act and which is nevertheless made compact.
The present invention provides an antitheft device which comprises a tag 10 for performing a theft preventing function upon an escape from a specified control area, and an attaching member 2 for attaching the tag 10 to a commodity 9. The attaching member 2 comprises a button 22, and a pin 21 projecting from the button 22 and movable into a housing 1 of the tag 10 through a pinhole 12a formed in the housing 1.
Arranged inside the housing 1 of the tag 10 are a clamp member 3 for clamping the pin 21 of the attaching member 2 as moved in through the pinhole 12a, an on-off switch 8 to be depressed by the button 22 of the attaching member 2, and a theft alarm operable under the control of on-off signals from the on-off switch 8.
The clamp member 3 has a clamp portion 34 for the pin 21 of the attaching member 2 to be inserted therethrough for clamping the pin 21 unremovably. The clamp member 3 is rotatably supported by a pivot provided inside the housing 1, permits the clamp portion 34 to be disengaged from the pin 21 when rotated about the pivot in one direction and is given an elastic repulsive force against the rotation.
The housing 1 is provided with an inlet passage 14 for an unclamping probe 7 for pushing the clamp member 3 into rotation toward the above-mentioned one direction. The on-off switch 8 comprises an actuator 82 having an outer end projecting outward from the housing 1 through a hole 12b formed in the housing 1, and a cylindrical guide portion 83 formed around a base end portion of the actuator 82 and providing the pivot for the clamp member 3.
The stepped cylindrical portion 17b provided in the conventional antitheft device for rotatably supporting the clamp member 3 thereon is omitted from the antitheft device of the present invention, while the on-off switch 8 is disposed at the corresponding position for the cylindrical guide portion 83 of the switch 8 to rotatably support the clamp member 3. When the tag 10 as attached to the commodity 9 is to be brought out of the specified control area, the salesclerk is notified of the situation by the antitheft function of the tag 10 as is the case with the conventional device.
The unclamping probe 7 is used for the salesclerk to remove the tag 10 from the commodity 9 as in the prior art. Stated more specifically, the forward end of the probe 7 is inserted into the space wherein the clamp member 3 is provided by way of the inlet passage 14 of the housing 1 to push the clamp member 3 with the forward end against the elastic repulsive force, where by the clamp member 3 is rotated in the above-mentioned one direction to thereby disengage the clamp portion 34 from the pin 21 of the attaching member 2 and unclamp the pin 21. Consequently, the attaching member 2 becomes removable.
If the pin 21 of the attaching member 2 is cut with the tag 10 affixed to the commodity 9, the removal of the button 22 of the attaching member 2 from the tag 10 frees the actuator 82 of the on-off switch 8 from the depression by the button 22, projecting the actuator 82 from the depressed position to a released position to turn off the switch which is closed. As a result, an on signal from the switch 8 is changed for an off signal, which is fed to the theft alarm, notifying salesclerks of the occurrence of theft. The signal is so processed as to hold the theft alarm out of operation when the attaching member 2 is removed by the salesclerk using the probe 7.
The cylindrical guide portion 83 of the on-off switch 8 is utilized in the antitheft device of the invention in place of the stepped cylindrical portion 17b provided in the conventional antitheft device for rotatably supporting the clamp member 3. The additional provision of the on-off switch 8 is therefore unlikely to make the housing 1 greater in size. Accordingly, the present device remaining as large as the conventional antitheft device is adapted to reliably prevent the commodity 9 from being stolen by cutting the pin 21 of the attaching member 2.